I had installed a JVC head unit in my '01 in order to get MP3 playback capability. After upgrading the head unit and all 4 speakers, I wasn't happy with the bass response. I didn't want to go through the effort of a custom sub & amp install, so I got the Kenwood powered sub. While it isn't going to rattle your windows, the Kenwood did a good job of filling in the low end.